Swimming at the 1979 Pan American Games – Men's 100 metre butterfly

The men's 100 metre butterfly competition of the swimming events at the 1979 Pan American Games took place on 7 July at the Piscina Olimpica Del Escambron. The last Pan American Games champion was Mike Curington of US.

This race consisted of two lengths of the pool, all in butterfly.

Results
All times are in minutes and seconds.

Heats
The first round was held on July 7.

Final
The final was held on July 7.